Effect of Microstructure on Machinability of Cast Irons—II

Abstract

Abstract The general investigation of the effect of microstructure on the machinability of cast iron reported in Part I was continued on structures of varying pearlite and graphite size but with the addition of about five per cent of free steadite, the iron - iron phosphide eutectic. Finally, straight malleable iron and one type of pearlitic malleable iron were studied. The straight malleable iron had a structure consisting of ferrite and nodular graphite while the pearlitic malleable structure consisted of recombined carbon, ferrite, and nodular graphite. The tool life, power requirements, and surface finish were determined for these structures, and comparisons are shown with the structures of Part I. By means of these data the expected machinability of a cast iron can be determined by comparing its microstructure with those presented in this and the previous paper.